Media captionHome Secretary Theresa May: "Discussions are ongoing as to what measures will be"

The government plans to exercise its right to opt out of 130 EU measures on law and order, Home Secretary Theresa May has told MPs.

She said current government thinking was to return control to the UK in two years under an opt-out agreed during Lisbon Treaty negotiations.

It would mean opting out of the European Arrest Warrant, which the Lib Dems supported at the last election.

Labour accused the government of having an "utterly confused" position.

Eurosceptic Tory MPs welcomed the announcement as a first step in the repatriation of powers to the UK.

The opt-out, agreed by the last government, means the government either has to pull out of all 130 EU crime and policing measures agreed before that treaty came in to force in 2009, or none of them.

In a statement to the House of Commons on Monday, Mrs May made it clear the government preferred the first option.

The government could subsequently opt back in to some of the measures, as long as the rest of the EU agreed.

However, Mrs May said discussions were ongoing as to what these measures would be.

She said: "It is the national interest that the government has taken this decision.

"The Government is clear that we do not need to remain bound by all of the pre-Lisbon measures.

"Operation shows that some pre-Lisbon measures are useful, some less so and some are now entirely defunct."

'Hokey cokey'

There would be no formal notification of the UK's decision to opt-out to the European Council until agreement was reached on a package for opting in, Mrs May said.

The Lib Dems are expected to push for the readoption of the European Arrest Warrant and renewed participation in EU-wide policing bodies.

BBC political correspondent Iain Watson said the issue could lead to further tensions within the coalition as the arrest warrant was opposed by the Conservatives during the last election.

Tory opponents say it has led to unfair trials abroad for Britons while the Lib Dems say it has been used effectively to return suspects, including teacher Jeremy Forrest earlier this month.

Shadow home secretary Yvette Cooper criticised the government's position as "utterly chaotic" because it was supporting an opt-out without being clear about which measures it would later want to opt back in to.

"It's like the government is playing is a giant game of hokey cokey and yet the fight against crime is at stake," she said.

Tory MP Dominic Raab, who wants powers returned to the UK, said the announcement showed the government wanted "focused cooperation not the blind loss of democratic control".

And fellow Conservative Michael Ellis congratulated Theresa May for "protecting the sovereignty of this country".

However, UKIP leader Nigel Farage was not convinced, describing the Home Secretary as "the modern day Grand Old Duke of York" in a statement.

He said: "She says she wants to opt out and then opt in again: I suspect nothing of substance will actually be achieved."

Responding to the home secretary's statement, the European Commission said: "This does not come as a surprise - the UK has right to request a block opt-out from police and judicial co-operation in criminal matters.

"The UK has indicated it wishes to exercise its rights under the (Lisbon) treaty.

"The commission will assess the consequences. The treaties also provide the possibility for the UK to opt back in to some or all of those provisions."